A patient sustains complete avulsion of C5–C6 nerve roots in a motorcycle accident causing upper trunk brachial plexus palsy. The most commonly used donor nerve for neurotization of the musculocutaneous nerve to restore elbow flexion is:
- A Intercostal nerve
- B Spinal accessory nerve (CN XI) ✓
- C Phrenic nerve
- D Contralateral C7 nerve root
Correct answer: B. Spinal accessory nerve (CN XI)
Explanation
The spinal accessory nerve (CN XI) is the preferred donor for neurotization of the musculocutaneous nerve (to restore elbow flexion via biceps) in upper trunk brachial plexus avulsion injuries because it is expendable (trapezius can be compensated), consistently available, and provides a relatively large axon count. It is transferred directly without an intervening graft in many cases. The phrenic nerve can compromise respiration; intercostals are used but provide weaker reinnervation; contralateral C7 requires a long nerve graft and prolonged reinnervation time.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.